"Kamen Rider W Returns" is a special series in the long-running Japanese franchise, Kamen Rider. It features two films that serve as a continuation of the story from the original Kamen Rider W series. The films focus on the characters Shotaro Hidari and Philip, who are the main protagonists, as they tackle new challenges and villains in the city of Futo. The first film, titled "Kamen Rider W Returns: Kamen Rider Accel," centers on the character Akiko Narumi and her partner Ryu Terui, who transforms into Kamen Rider Accel. The second film, "Kamen Rider W Returns: Kamen Rider Eternal," explores the backstory of the antagonist Kamen Rider Eternal, providing deeper insights into the series' lore and character development.